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1.
Diana Hurdowar-Castro Ioannis Tsanis Ilmar Simanovskis 《Journal of Great Lakes research》2007,33(1):232-252
A 3D transport model is used to perform a comparative analysis of several potential drinking water intakes located along the northwest shore of Lake Ontario between Toronto and Oshawa. The model is specifically used to assess each intake under both long- and short-term transport of a potential pollutant release from the Pickering Nuclear Generating Station and potential and actual pollutant releases from local land sources respectively. A model based on a 500 m grid resolution is calibrated using data collected in the aftermath of the 1992 tritium spill at the Pickering Nuclear Generation Station and subsequently used to simulate long-term transport. A model based on a 100 m grid resolution is verified using drogue studies and used to simulate short-term transport events. Both models are used to assess pollutant levels at each of nine potential intake locations under different wind scenarios and pollutant releases. Field data for the study included water quality and flow measurements from local sewers and rivers, and estimates of pollutant levels from the local waste water treatment plants. This paper describes the model setup for both the long-term and short-term transport models, calibration using field data, long-term transport modeling, short-term transport modeling, and the comprehensive analysis approach used to evaluate the nine potential intake locations proposed. Results indicated that four intakes in particular outperformed other intake locations by maintaining bottom pollutant levels within governmental standards and warning times that exceeded 20 hours. 相似文献
2.
Cross‐docking replaces traditional warehousing, enabling continuous flow of items without storage. Here we model location‐distribution networks, that include cross‐docking facilities, to obtain the latter's impact on the supply chain. We formulate optimization models to minimize total cost in three multi‐echelon networks, each model generalizing the preceding one. The first includes a single manufacturer, one product type, and multiple customers. Cross‐docks are to be located between origin and destinations. Besides solving optimally, a tool for quantitative analysis of direct‐shipment decisions is developed. The second model considers more than one product: We determine a cost‐effective sequence of items for indirect shipment (via cross‐docks). Finally, in a network with multiple origins, optimal solutions are obtained for 40 medium‐sized and larger examples. 相似文献
3.
流溪河灌区工程渠首枢纽计算机监控系统开发与研建 总被引:1,自引:0,他引:1
流溪河渠首枢纽计算机监控系统在自行开发的现场总线工业局域网及专用智能终端、冗余管理和故障诊断专家系统的硬件环境下,在分别由监控系统(含设备层与上位机在线监控系统)和管理系统(由离线管理与服务器上的查询服务系统组成)软件的支持下,实现了对枢纽工程3座水闸47孔闸门的运行和管理,具有自动监测、自动量水、自动控制及系统重构等功能.现已以每天24h不间断地运行了2年,顺利地完成了枢纽工程的调洪、调水等日常调度与运行工作. 相似文献
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利用有限差分法,对某泵站不规则底板的地基应力进行计算分析,并结合实测数据,得出在不同本构模型及接触情况下地基应力分布规律。 相似文献
6.
通过对“模型鄱阳湖”实体模型工程模拟技术中的几何比尺变率、模型阻力相似、模型时间比尺、模型控制及量测技术等方面研究分析,探求“模型鄱阳湖”工程技术上的可行性. 相似文献
7.
随着全球经济的快速发展和陆地自然资源的日趋紧缺,海洋开发利用已成为许多国家重要的经济战略。我国是海洋大国,丰富的岛屿资源是我国海洋开发的重要依托。开发海岛资源,主要从发展海洋渔业入手,但不同的发展模式显示出不同的发展前景。在对山东省长岛县和辽宁省长海县的经济发展模式做简要对比分析后,探寻海岛经济可持续发展规律,并对相关问题进行思考。 相似文献
8.
三水源新安江模型在南方湿润地区精度较高,在北方半湿润半干旱地区的应用经验不多。应用三水源新安江模型对黄河三门峡~小浪底区间(以下简称三小区间)进行了产汇流模拟计算。经过对1980年以来的7次洪水进行产汇流模拟计算,小浪底站平均确定性系数0.85,可用于小浪底水库入库洪水预报。 相似文献
9.
南水北调中线全线自流,各渠段水头分配很严格,穿黄隧洞作为路线上的关键工程,正确估算其水头损失非常重要。文章利用1:29.17的正态模型对穿黄隧洞的沿程水头损失系数λ与Re的关系进行了研究;对穿黄隧洞的总水头损失进行了测量,并与计算结果进行比较。所获得的设计与校核流量下的总水头损失值,可供工程设计、校核参考。 相似文献
10.
For more than forty years, the herbicide atrazine has been used on corn crops in the Lake Michigan basin to control weeds. It is usually applied to farm fields in the spring before or after the corn crop emerges. A version of the WASP4 mass balance model, LM2-Atrazine, was used to assess the impact of the historical and future usage of this chemical on lake water concentrations. Long-term model forecasts were performed under various sensitivity and potential management scenarios. The model was calibrated to available lake data and results indicate that atrazine, under average conditions, is decaying very slowly in the lake (0.009/year). This kinetic decay translates into a half-life estimate of 77 years. If the average condition scenario were assumed to remain constant into the future and reflective of conditions in January 1, 2005, it is expected that the lake (excluding Green Bay) would eventually reach a volume-weighted average atrazine concentration of approximately 67 ng/L in the year 2157 (current model prediction is 48 ng/L for year 2011). These forecasted lake-wide concentrations are below known water quality criteria for the protection of aquatic ecosystems. 相似文献